FACTORS THAT INFLUENCE THE ELIGIBILITY OF CASES FOR INCLUSION IN CLINICAL-TRIALS

Background: It is important to minimize the incidence of ineligible ca ses to improve the quality of clinical trials. To determine factors wh ich may influence the incidence of ineligible cases, the incidence of and reasons for ineligibility in clinical trials were retrospectively analyzed. Methods: We retrospectively examined the incidence of and re asons for ineligibility for inclusion in eight clinical trials conduct ed by the Lung Cancer Chemotherapy Study Group of the Japan Clinical O ncology Group and four trials financed by trust funds from a pharmaceu tical company. Results: In these 12 clinical studies, the incidence of ineligibility was 4.2% (32/762) (range 0-10.6%). Specific factors tha t might influence the incidence of ineligible cases were then analyzed . There was a significant difference in the incidence of ineligibility between the methods of registration (P < 0.05). The incidences using a central registration and without using a central registration system were 2.8% (9/322) and 5.2% (23/440) respectively. We also analyzed in eligible cases in clinical studies published in the Journal of Clinica l Oncology, In clinical studies published in the Journal of Clinical O ncology recently and 10 years ago, the incidences of ineligible cases were 5.0% (942/18 878) and 4.1% (206/4995) respectively, In clinical s tudies on lung cancer published in the Journal of Clinical Oncology fr om 1984 to 1995, the incidence of ineligible cases was 4.7% (900/19 11 6), There was no significant difference in the incidence of ineligible cases between our 12 studies and the Journal of Clinical Oncology cli nical studies by the chi(2) test (P > 0.05). Conclusions: We conclude that the incidence of ineligible cases in our studies is similar to th at in clinical trials published in the Journal of Clinical Oncology, C entral registration systems are useful for checking for ineligibility, and to increase the quality of clinical trials.